How Thoroughbreds Convert Air Into Blazing Speed

Bryan Christie Design

There are sprinters and there are distance runners, but the thoroughbreds charging down the track this month at the Kentucky Derby (sometimes called the fastest two minutes in sport) need to be both. The race stretches a grueling mile and a quarter, so those horses have to be machines that convert air into speed.

1// Slow-Twitch muscle uses oxygen more efficiently, which aids endurance. Thorough­breds have nearly twice as many slow­ twitch fibers as sprinty quarter horses, so they can clock speeds up to 40 mph even on the home stretch.